Rust

Check Whether an SSH Channel is Open

Demonstrates the Chilkat Ssh.ChannelIsOpen method, which reports whether a channel number identifies a channel Chilkat currently considers open for application I/O. The only argument is the channel number. This example checks the channel before and after sending CLOSE.

Background: Because one SSH connection can carry many channels with independent lifetimes, code that manages several needs a way to ask whether a given one is still usable. This returns false for invalid or nonexistent channel numbers, after a local Disconnect, once remote closure is processed, and immediately after ChannelSendClose — which marks the channel locally closed without waiting for the remote side.

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Rust


// Demonstrates the Ssh.ChannelIsOpen method, which reports whether a channel number identifies
// a channel Chilkat currently considers open for application I/O.  The only argument is the
// channel number.

let ssh = chilkat::Ssh::new();

let ssh_port = 22;
if ssh.connect("ssh.example.com", ssh_port).is_err() {
    println!("{}", ssh.last_error_text());
    return;
}

// Normally you would not hard-code the password in source.  You should instead obtain it
// from an interactive prompt, environment variable, or a secrets vault.
let password = "mySshPassword".to_string();

if ssh.authenticate_pw("mySshLogin", &password).is_err() {
    println!("{}", ssh.last_error_text());
    return;
}

// Open a session channel.  A negative return value indicates failure.
let channel_num = ssh.open_session_channel();
if channel_num < 0 {
    println!("{}", ssh.last_error_text());
    return;
}

if ssh.channel_is_open(channel_num) {
    println!("The channel is open.");
} else {
    println!("The channel is not open.");
}

// Send CLOSE, which immediately marks the channel locally closed.
if ssh.channel_send_close(channel_num).is_err() {
    println!("{}", ssh.last_error_text());
    return;
}

if ssh.channel_is_open(channel_num) {
    println!("Still open.");
} else {
    println!("The channel is now closed.");
}

ssh.disconnect();